This is almost the exact route that I went. I just finished my MA degree in psych research (not necessarily "Experimental Psych" or such as the program was more tailored to your interests, so I balanced quant and qual methods). I, too, had very limited research experience as an UG, but did have some clinical experience. I heard the same thing re: my grad applications- clinical experience is nice, but research experience is much better and most likely required. So I actually switched from a clinical MA to a research MA specifically to get more research training, exposure, and general knowledge.
I think you should carefully evaluate what you long-term goals are, and also be open to change. I was 100% determined for a CLinical PhD track, thinking this program would set me up for that. Then came a baby and some other life decisions and I am re-thinking my plans and pursuing other social science PhD programs such as sociology or even Counselor Education where the job prospects seem much better. In sum, if you had little to none research experience as UG, definitely want to go on for a PhD because you are interested in research, then I think its a smart move to set-up a foundation and gain more experience.
EDIT: As a side note, a MA degree in research methods or the like might be a good thing not only setting you up for education, but also because it is broad enough where you can apply research methods to almost anything- medicine, social sciences, business (e.g. marketing research or consumer psychology). Just need to figure out what path you want or gain exposure to a wide array to make an informed decision or even build up a diversified CV